Testosterone Replacement Therapy Does Not Increase Prostate Cancer Risk in Hypogonadal Men

Several recent studies have cast doubt upon the benefits of long-term androgen deprivation therapy and the risks of naturally high testosterone levels for prostate cancer patients.

Now, new research casts more doubt upon the notion that testosterone replacement therapy increases the risk that men will develop prostate cancer, even if men use such therapy for years.

The research team, which published its findings in The Journal of Urology, followed 3 parallel, prospective, ongoing, cumulative registry studies with a total of 1,023 hypogonadal men. A pair of those cohorts consisted of men who were being treated by urologists since 2004. The last consisted of men receiving the same treatment from an academic andrology center since 1996.

Patients in all groups received testosterone replacement therapy, via undecanoate injections, at 12-week intervals, when their total testosterone levels fell below 12.1 nmol/l (350 ng/dl) and they experienced physical symptoms of hypogonadism.

Patients received prostate exams before treatment and ongoing monitoring during a follow-up period that lasted a maximum of 17 years (1996 to 2013) and a median of 5 years. The mean age at baseline was 58 years for patients of the urologists and 41 years for patients of the andrology center.

A total of 11 patients who visited the 2 urology offices were diagnosed with prostate cancer, a figure that translates into 2.3% of all patients who visited 1 office and 1.5% of all patients who visited the other. The incidence per 10,000 patient-years was 54.4 and 30.7, respectively.

No prostate cancer was reported by the andrology center.

“Although considerable evidence exists indicating no relationship between testosterone and increased risk of developing prostate cancer, decades of physician training with the notion that testosterone is fuel for prostate cancer made it difficult to dispel such fallacy and the myth continued to persist,” said Ahmad Haider, MD, PhD, a urologist in Bremerhaven, Germany, and the lead investigator of the study.

Haider and his co-authors — who all disclosed financial ties to companies that make testosterone supplements — acknowledged the limitations inherent to the design of their study, which lacked a control arm filled with similar patients.Haider also acknowledged that doctors were likely to keep on worryingabout testosterone replacement and prostate cancer until definitive long-term data from a randomized, controlled trial proved it safe.

“Considerable skepticism remains throughout the medical community, and this is an expected natural and acceptable path of medical and scientific discourse,” he said.

Still, he added,“In view of the current evidence, clinicians are compelled to think this over and cannot justify withholding testosterone replacement therapy in hypogonadal men, also in men who have been successfully treated for prostate cancer.”

The new study comes just a few months after a randomized trial presented at the American Society for Radiation Oncology’s 56^th Annual Meeting found that prostate cancer patients who received 36 months of androgen deprivation therapy (ADT) enjoyed significantly lower quality of life (but received no compensating medical benefits) when compared to patients who received the treatment for just 18 months.

This summer, moreover, a large study in JAMA Internal Medicine concluded that ADT does not extend the lives of men with early-stage prostate cancer.

Meanwhile, another study that examined the link between innate levels of testosterone and prostate cancer concluded this spring that low testosterone levels — not high testosterone levels — are associated with increased chances of developing the disease.